Tosoh Corporation of Japan has a proud history of innovation and leadership in size exclusion liquid chromatography (SEC). Silica-based TSKgel® SW-type columns are known worldwide for their reliability and suitability for the analysis of proteins, peptides and other biological macro-molecules. Polymethacrylate-based TSKgel PW-type columns are equally well known for determining and monitoring the molecular mass distribution of water-soluble polymers. A third product line, TSKgel Alpha and SuperAW columns, is dedicated to the analysis of polar-organic soluble polymers. Tosoh′s foray in SEC started out in the early days of HPLC with the TSKgel H-type column line for the analysis of organic-soluble polymers by gel permeation chromatography (GPC). Other the years, all TSKgel size exclusion column products have benefited from a relentless focus on continuous improvements as well as innovative developments in particle design, surface chemistry, and column technology.